Field of the Invention
Embodiments of the present invention generally relate to methods of making side gap layers of a damascene write pole.
Description of the Related Art
The heart of a computer is a magnetic disk drive which typically includes a rotating magnetic disk, a slider that has read and write heads, a suspension arm above the rotating disk and an actuator arm that swings the suspension arm to place the read and/or write heads over selected circular tracks on the rotating disk. The suspension arm biases the slider into contact with the surface of the disk when the disk is not rotating but, when the disk rotates, air is swirled by the rotating disk adjacent an air bearing surface (ABS) of the slider causing the slider to ride on an air bearing a slight distance from the surface of the rotating disk. When the slider rides on the air bearing, the write and read heads are employed for writing magnetic impressions to and reading magnetic signal fields from the rotating disk. The read and write heads are connected to processing circuitry that operates according to a computer program to implement the writing and reading functions.
In order to meet the ever increasing demand for improved data rate and data capacity, researchers have developed perpendicular recording systems, which record data as magnetizations oriented perpendicular to the plane of the magnetic disk. The magnetic disk has a magnetically soft underlayer covered by a thin magnetically hard top layer. The perpendicular write head has a write pole with a very small cross section and a return pole having a much larger cross section. A strong, highly concentrated magnetic field emits from the write pole in a direction perpendicular to the magnetic disk surface, magnetizing the magnetically hard top layer. The resulting magnetic flux then travels through the soft underlayer, passing back through the magnetically hard top layer and returning to the return pole where the magnetic flux is spread out and too weak to erase the signal recorded by the write pole.
At the ABS, the write pole is surrounded by side gap layers. The side gap layers prevent the write pole from writing to adjacent data tracks and magnetic write field from leaking out. Sometimes the side gap layers have a bumpy surface adjacent to the write pole, causing the bevel angle measurement to be very difficult. The bumpy surface of the side gap layers may also impact magnetic properties of films subsequently grown thereon.
Therefore, there is a need in the art for an improved method for forming the side gap layers.